Device for sterilizing contaminated materials

ABSTRACT

An apparatus for disinfecting or sterilizing contaminated materials including a first worm screw ( 15 ) inside a pretreatment chamber ( 14 ) and a second worm screw ( 17 ) arranged close to the end of the first worm screw ( 15 ) and extending inside a treatment chamber ( 16 ). Elements are provided for sealing both ends of the treatment chamber ( 16 ) so that an elevated pressure can be maintained in the treatment chamber. Energy can be introduced into the treatment chamber in a controlled manner to supply or produce steam sufficient to create and maintain an elevated pressure and temperature needed to disinfect and/or sterilize the contaminated material. The pretreatment chamber ( 14 ) and the treatment chamber ( 16 ) are connected to each other by a reversing component ( 1 ) having two tube sections ( 2, 3 ) which form an angle relative to each other and which are secured to the pretreatment chamber ( 14 ) and the treatment chamber ( 16 ) by flanges ( 4, 5 ). The apparatus offers a high degree of flexibility with regard to mounting and modification of the angular position of the pretreatment and treatment chambers.

BACKGROUND OF THE INVENTION

The invention relates to a device for disinfecting and/or sterilizingcontaminated, in particular infected materials, having a first wormconveyor that runs inside a pretreatment chamber and a second wormconveyor that is mounted at the end of the first worm conveyor and runsinside a treatment chamber, wherein means are present for sealing thetwo end areas of the treatment chamber to build up elevated pressure.Energy can be introduced into the treatment chamber in a defined way,water vapor supplied and/or generated and an elevated pressure and thetemperature necessary for disinfecting and/or sterilizing can be builtup and maintained.

In the German patent application with the official file number 197 17839.1-41, a high temperature disinfecting and/or high temperaturesterilizing device is described which is especially suitable forhospital waste and in which the waste is supplied by way of a receivinghopper and a crusher with worm conveyors mounted in succession. Thefirst worm conveyor runs inside a pretreatment chamber, wherein aheating of the material to be treated occurs in the pretreatmentchamber. This first worm conveyor is mounted so that is inclineddiagonally upward in its conveyor direction which safely assures thatcontaminated fluid that is introduced into the disposal hopper can onlycollect in the area below the disposal hopper and/or in a low-lyingsection of the worm conveyor.

The second worm conveyor is mounted on the end of the first wormconveyor and runs inside a treatment chamber that is arrangedhorizontally. The actual disinfecting and/or sterilizing process takesplace inside the treatment chamber. To do this, means are provided forsealing the two end areas of the treatment chamber to build up anelevated pressure.

In this known device, the pretreatment chamber and the treatment chamberare connected to each other as a single unit. Thus, there are noassembly means present, by means of which the two chambers can beseparated from each other in a simple way. This means that e.g. repairwork involving the chambers can sometimes only be carried out with greateffort.

The patent U.S. Pat. No. 3,464,342 already discloses a device fortreatment of chicken feathers and the like having a first worm conveyormounted inside a pretreatment chamber and a second conveyor that ismounted near the end of the first worm conveyor and runs inside atreatment chamber. The device has means for sealing the end of thetreatment chamber, so that an elevated pressure is built up inside it.To do this, defined energy can be supplied by means of steam in order toprovide the necessary pressure and the necessary temperature forremoving moisture from the material that has been introduced into theapparatus. The pretreatment chamber and the treatment chamber areconnected to each other at an angle by a reversing component which isfastened by means of a flange connection so that it can be disconnectedon one side to the end section of the pretreatment chamber and on theother side to a connecting pipe that opens vertically into the treatmentchamber.

SUMMARY OF THE INVENTION

It is therefore the object of the invention to provide a device of thisgeneral type for treatment of contaminated, and in particular infected,materials that offers great flexibility with respect to its installationcapability and with respect to the ability to change the angularposition of the pretreatment chamber and the treatment chamber to eachother.

The object is achieved by a device of this general type, in which thesecond worm conveyor basically extends inside the entire area of theassociated tube section.

Because of this, it is possible to separate the pretreatment chamber andthe treatment chamber from each other by simple disassembly of thereversing component. This makes it easier, for example, to replace oneof the two worm conveyors.

In addition, the inclination of the pretreatment chamber can be changedeasily by replacing the reversing component with a reversing componentin which the two tube sections are arranged at a different angle to eachother. This can occur, for example, in order to optimize the area withinthe pretreatment chamber in which fluid collects. In addition, by simplyusing an appropriate reversing component, the transition surface of thetwo tube sections is easy to change. Another advantage is that if thereis wear on the reversing components, the pretreatment tube does not haveto be changed and vice versa.

Preferably, the two tube sections of the reversing component arestraight in longitudinal direction. In this case, for example, thesecond worm conveyor that is mounted in the treatment chamber can alsoextend into the corresponding tube section of the reversing component.This tube section can have another flange that is located at the end ofthe tube section lying opposite the first flange. On this other flange,e.g. a drive for the second worm conveyor can be mounted.

The reversing component can have an inlet neck for samples. In addition,connecting nipples for measuring sensors can also be provided on thereversing component, in order to measure the temperature, the pressure,the moisture content or the fill level in the treatment chamber, forexample.

A preferred angle range of the reversing component lies between 20° and45°. This angle approximately corresponds to the angle at which thepretreatment chamber is tilted upward in the conveyor device, since thetreatment chamber is preferably mounted so that it is horizontal.

Preferably means for sealing the treatment chamber are mounted insidethe reversing component. Because of the simple replacement capability ofthe reversing component, the sealing means can also be changed in asimple manner. This permits great flexibility in the use of the device.Therefore, for example, a cone-shaped ring can be mounted in the endarea of the first worm conveyor inside the reversing component in such away that the material is compressed.

The first worm conveyor is preferably surrounded with a heating elementin order to heat up the material to be treated while it is beingconveyed by the worm.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, the invention will be explained in further detail withrespect to an embodiment of the apparatus according to the invention,with reference being made to the figures, which show:

FIG. 1, a schematic side view of a reversing component according to theinvention that is connected with a pretreatment chamber and a treatmentchamber that are only indicated and not shown in detail.

FIG. 2, a schematic top view of the reversing component according toFIG. 1;

FIG. 3, a schematic general representation of the device according tothe invention having the reversing component according to FIG. 1;

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 shows a reversing component 1, that has two tube sections 2 and3. The two tube sections 2 and 3 are connected to each other so thatthey can communicate. On its free end, tube section 2 has a flange 4. Oneach of its two ends, tube section 3 has a flange 5 or 6. These flanges4, 5 and 6 have openings, e.g. indicated with 7 (FIG. 2) so that theycan be screwed together.

Tube section 3 is provided with a tube 8 to input samples. In addition,in longitudinal direction on both sides, tube section 3 has theeconnecting pieces for connection of measuring sensors, of whichconnecting pieces 9, 10, 11 and 12 are shown in FIG. 1 and FIG. 2. Tubesection 2 has two other connecting pieces 13 and 13′ for connectingmeasuring sensors.

The reversing component 1 also has a cone-shaped ring 19 that reducesthe free passage cross section of tube section 2 in conveyor direction.

Other components of a device according to the invention are shown inFIG. 1 in dotted lines. This involves a pretreatment chamber 14 that isonly partially shown, to which tube section 2 is mounted by way offlange 4. A first worm conveyor 15 is located in pretreatment chamber14, which can also extend in, up to the transition piece.

Tube section 3 is fastened to a treatment chamber 16 by flange 5. Asecond worm conveyor 17 runs inside treatment chamber 16 and tubesection 3. The second worm conveyor 17 is moved by drive 18 that isfastened to tube section 3 by means of flange 6.

FIG. 3 shows the device schematically in an overall representation. Inparticular, this diagram shows an input unit 20 with a crusher that isnot shown and an ejector 21 and a drive 22 of the first worm conveyor15. In addition, another cone-shaped ring 23 is shown, that is mountedon the output side within treatment chamber 16.

The embodiment of the invention shown in the figures is designed tofunction in the following manner.

Contaminated material is supplied by way of inlet unit 20 to the firstworm conveyor 15, which extends inside pretreatment chamber 14. Wormconveyor 15 is surrounded by a heating element (not shown) so that thematerial to be treated is heated in a defined manner while it is beingconveyed by worm conveyor 15. In addition, a compression of the materialalso takes place in worm conveyor 15 such that a sealing material plugis created in its end area. This occurs on one hand because of the factthat the pitch angle of worm conveyor 15 is reduced in its end area. Onthe other hand, the compression is achieved by a cone-shaped ring 19.

Worm conveyor 15 transports the material to the second worm conveyor 17which extends essentially inside the treatment chamber 16, but alsoinside tube section 3. A stress relief and loosening of the structure ofthe material to be treated takes place inside treatment chamber 16. Thesecond worm conveyor 17 is also surrounded by a heating element and isdesigned for actually treating the material. Energy can be introduced inpulses into treatment chamber 16, in addition steam can be introducedand/or generated and an elevated pressure built up and maintained forthe temperature necessary for disinfecting and/or sterilizing. In turn,worm conveyor 17 compresses the material in its end area to a secondsealing plug of material due to the decreased pitch of worm 17 and bymeans of the cone-shaped ring 23. Because of this, the elevated pressurerequired for disinfecting and/or sterilizing can be maintained for adefined period of time between the two material plugs of worm conveyors15, 17, which act as seals.

Since the first worm conveyor 15 is mounted at an angle of approx. 30°to the horizontal plane, a forward conveyance of the material results.This very securely prevents contaminated fluid from flowing unnoticedout of the area below the input unit into the system, and the processfrom occurring without treatment and/or with insufficient treatment.

Because of the fact that reversing component 1 can be easily replaced,various parameters of the device according to the invention can bemodified in a simple manner. This includes, e.g. the pitch of first wormconveyor 15 and the means 19 in reversing component 1 for sealingtreatment chamber 16. With the device according to the invention,contaminated materials, preferably hospital waste, but also, forexample, clarifier sludge, contaminated earth, as well as foodstuffssuch as grains and spices can be treated, safely disinfected and evensterilized depending on requirements and on the system layout.

What is claimed is:
 1. An apparatus for disinfecting or sterilizingcontaminated material comprising a pretreatment chamber, a first wormconveyor inside the pretreatment chamber, a treatment chamber, and asecond worm conveyor mounted adjacent a discharge end of the first wormconveyor and extending through the treatment chamber, means for sealingend areas of the treatment chamber to enable an elevated pressure to bemaintained in the treatment chamber, and means for controlledintroduction of energy into the treatment chamber in order to supply orgenerate steam and build up an elevated pressure and temperature neededfor disinfection or sterilization of the contaminated material, whereinthe pretreatment chamber and treatment chamber are connected to eachother by a reversing component comprising two tube sections arranged atan angle to each other, respective tube sections of said reversingcomponent being releasably mounted to the treatment chamber and to thepretreatment chamber by flanges so that the reversing component can bedisconnected, and wherein the second worm conveyor extends insideessentially the entire area of the respective reversing component tubesection connected to the treatment chamber.
 2. An apparatus according toclaim 1, wherein the two tube sections of the reversing component areeach linear tubes.
 3. An apparatus according to claim 1, wherein tubesection connected by a flange to the treatment chamber has a secondflange at an end opposite the flange which connects the tube section tothe treatment chamber.
 4. An apparatus according to claim 3, furthercomprising a drive mounted on said second flange for driving said secondworm conveyor.
 5. An apparatus according to claim 1, further comprisingan inlet nipple on said reversing component for introducing for samplesinto the treatment chamber.
 6. An apparatus according to claim 1,further comprising at least one connecting nipple on said reversingcomponent, each connecting nipple receiving a measuring sensor formeasuring at least one parameter selected from the group consisting ofthe temperature, the pressure, the moisture level and the fill level inthe reversing component.
 7. An apparatus according to claim 1, whereinthe two tube sections of the reversing component form an angle of from20° to 45° with each other.
 8. An apparatus according to claim 7,wherein the treatment chamber is at least substantially horizontal andthe pretreatment chamber is inclined diagonally upward in the conveyingdirection of said first worm conveyor.
 9. An apparatus according toclaim 1, wherein said sealing means comprise means mounted inside thereversing component for sealing the treatment chamber.
 10. An apparatusaccording to claim 9, wherein the sealing means comprise a cone-shapedring mounted adjacent a discharge end of the first worm conveyor suchthat a compressed plug of contaminated material to be treated is formedadjacent said ring.